Manufacturing method for caseless capacitors

Abstract

To provide a method for manufacturing a case-less capacitor, capable of improving the positioning accuracy of bus bars with respect to the outer surface of a sealing portion without a case.SOLUTION: A method for manufacturing a case-less capacitor 1 includes: a first step of placing, in a cavity 50 of a mold 5, a capacitor element 10 to which a pair of bus bars 2 are connected and which is fixed to a metal plate 3 and bringing the metal plate 3 into contact with the mold 5; a second step of injecting a resin 4 into the cavity 50 to bury the capacitor element 10 in the resin 4 and curing the resin 4 while part of each of the pair of bus bars 2 is projected from the resin 4, thereby obtaining a molding 1; and a third step of removing the molding 1 from the mold 5. The mold 5 has a contact surface 6 with which the metal plate 3 contacts in the cavity 50, and a restriction part 7 which restricts the movement of the metal plate 3 along the contact surface 6.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] FIELD OF THE DISCLOSURE This disclosure relates generally to a method for manufacturing a caseless capacitor, and more particularly to a method for manufacturing a resin-based caseless capacitor. [Background technology]

[0002] Patent Document 1 discloses a dry-type metallized film capacitor. This dry-type metallized film capacitor is formed by overlapping and winding a pair of metallized films, spraying metallikon metal on both end faces to form electrode lead portions on a capacitor element, joining an external lead wire to the capacitor element, housing the capacitor element in a resin case, and filling and curing a thermosetting resin. In the dry-type metallized film capacitor, the external lead wire is bent into a key shape toward the capacitor element, and a support plate is inserted into the L-shaped portion of the external lead wire, which is then housed and fixed in the resin case. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2000-049040 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, the dry metallized film capacitor of Patent Document 1 has a problem in that it is difficult to reduce the weight because it uses a resin case and a support plate in addition to the thermosetting resin. Also, the dry metallized film capacitor of Patent Document 1 does not particularly consider the positional accuracy of the external lead wires relative to the outer surface of the resin case.

[0005] An object of the present disclosure is to provide a method for manufacturing a caseless capacitor that does not include a case and that can improve the positional accuracy of the bus bars relative to the outer surface of the sealing portion. [Means for solving the problem]

[0006] A method for manufacturing a caseless capacitor according to one embodiment of the present disclosure includes a first step of placing a capacitor element, to which a pair of bus bars are connected and fixed to a metal plate, in a cavity of a molding die and bringing the metal plate into contact with the molding die, a second step of injecting resin into the cavity to embed the capacitor element in the resin and harden the resin in a state in which each of the pair of bus bars protrudes from the resin to obtain a molded product, and a third step of removing the molded product from the molding die. The molding die has a contact surface with which the metal plate comes into contact in the cavity and a restricting portion that restricts movement of the metal plate along the contact surface. Effect of the Invention

[0007] According to the present disclosure, without providing a case, it is possible to improve the positional accuracy of the bus bar with respect to the outer surface of the sealing portion. [Brief description of the drawings]

[0008] [Figure 1] Fig. 1A is a schematic plan view showing a step of a method for manufacturing a caseless capacitor according to a first embodiment, and Fig. 1B is a schematic front view showing a step of the method for manufacturing the caseless capacitor according to the first embodiment. [Diagram 2] 2A and 2B are schematic plan and cutaway front views showing a step in a method for manufacturing the caseless capacitor according to the embodiment of the present invention. [Diagram 3] 3A and 3B are schematic plan and cutaway front views showing a step of a method for manufacturing the caseless capacitor according to the embodiment of the present invention. [Figure 4] 4A, 4B, and 4C are schematic plan, front, and perspective views of the caseless capacitor shown in FIG. [Diagram 5]Fig. 5A is a schematic plan view showing a step of a method for manufacturing a caseless capacitor according to a second embodiment of the present invention, and Fig. 5B is a schematic cutaway front view showing a step of the method for manufacturing the caseless capacitor according to the second embodiment. [Figure 6] Fig. 6A is a schematic plan view showing a step of a method for manufacturing a caseless capacitor according to a third embodiment, Fig. 6B is a schematic cutaway front view showing a step of a method for manufacturing the caseless capacitor according to the third embodiment, and Fig. 6C is a schematic enlarged cross-sectional view of part C in Fig. 6B. [Figure 7] Fig. 7A is a schematic plan view showing a step of a method for manufacturing a caseless capacitor according to a fourth embodiment of the present invention, and Fig. 7B is a schematic cutaway front view showing a step of a method for manufacturing the caseless capacitor according to the fourth embodiment. [Figure 8] Fig. 8A is a schematic plan view showing a step of a method for manufacturing the caseless capacitor according to the fifth embodiment, and Fig. 8B is a schematic cutaway front view showing a step of the method for manufacturing the caseless capacitor according to the fifth embodiment. [Figure 9] Fig. 9A is a schematic plan view showing a step of a method for manufacturing a caseless capacitor according to a sixth embodiment, and Fig. 9B is a schematic cutaway front view showing a step of a method for manufacturing the caseless capacitor according to the sixth embodiment. [Figure 10] Fig. 10A is a schematic plan view showing a step of a method for manufacturing the caseless capacitor according to the seventh embodiment, and Fig. 10B is a schematic cutaway front view showing a step of the method for manufacturing the caseless capacitor according to the seventh embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] 1. Overview First, an overview of the caseless capacitor 1 according to this embodiment will be described with reference to the drawings. Each figure is a schematic diagram, and the size of each component in the figure does not necessarily reflect the actual size. Although arrows defining "upper", "lower", "left", "right", "front" and "rear" are illustrated in the figures, these arrows are illustrated only for convenience of explanation, and are not intended to limit the direction of the caseless capacitor 1, and do not have any substance. In the following, "plan view" means a view along the up-down direction, "side view" means a view along the left-right direction, and "front view" means a view along the front-rear direction.

[0010] As shown in FIGS. 4A to 4C, caseless capacitor 1 includes a capacitor element 10, a pair of bus bars 2, a metal plate 3, and a sealing portion 40.

[0011] The capacitor element 10 is of a wound type or a laminated type. In this embodiment, a wound type capacitor element 10 is used. The wound type capacitor element 10 is formed by winding a metallized film. The laminated type capacitor element 10 is formed by laminating metallized films.

[0012] The capacitor element 10 has a first end surface electrode 11 and a second end surface electrode 12. The first end surface electrode 11 and the second end surface electrode 12 are formed of a multi-layered metal coating. The multi-layered metal coating is formed by, for example, a metal spraying method. The first end surface electrode 11 and the second end surface electrode 12 are provided at both ends of the capacitor element 10 in the front-rear direction. That is, the first end surface electrode 11 is provided at the front end of the capacitor element 10. The second end surface electrode 12 is provided at the rear end of the capacitor element 10.

[0013] The pair of busbars 2 are a first busbar 21 and a second busbar 22. The first busbar 21 and the second busbar 22 are conductive members extending in the up-down direction. The first busbar 21 is connected to the first end surface electrode 11. The second busbar 22 is connected to the second end surface electrode 12. The first busbar 21 and the second busbar 22 are arranged side by side in the front-rear direction and parallel to each other in the up-down direction.

[0014] The metal plate 3 is disposed below the capacitor element 10. The metal plate 3 faces the capacitor element 10 via an insulating layer 42. The insulating layer 42 has electrical insulation properties. In this manner, with the insulating layer 42 interposed between the metal plate 3 and the capacitor element 10, the metal plate 3 is not in contact with either the first end surface electrode 11 or the second end surface electrode 12.

[0015] The sealing portion 40 seals the capacitor element 10. That is, the capacitor element 10 is embedded in the sealing portion 40. In this embodiment, the sealing portion 40 has a rectangular parallelepiped shape. Specifically, the sealing portion 40 has an upper surface 40a, a lower surface 40b, a left surface 40c, a right surface 40d, a front surface 40e, and a rear surface 40f. A pair of bus bars 2 protrude upward from the upper surface 40a. The metal plate 3 is exposed downward from the lower surface 40b.

[0016] By applying a voltage between the pair of bus bars 2, the caseless capacitor 1 can be charged.

[0017] Here, the length of the sealing portion 40 in the left-right direction is W, the length in the front-rear direction is L, and the length in the up-down direction is H. If the distance between the bus bar 2 and the left surface 40c of the sealing portion 40 is WL, and the distance between the bus bar 2 and the right surface 40d of the sealing portion 40 is WR, then WL+WR=W. If the distance between the first bus bar 21 and the front surface 40e of the sealing portion 40 is LF, the distance between the first bus bar 21 and the second bus bar 22 is L0, and the distance between the second bus bar 22 and the rear surface 40f of the sealing portion 40 is LB, then LF+L0+LB=L.

[0018] When manufacturing the caseless capacitor 1, the higher the positional accuracy of the busbar 2 relative to the outer surface of the sealing portion 40, the better. Specifically, when repeatedly manufacturing the caseless capacitor 1, it is preferable that each of the above-mentioned distances WL, WR, LF, and LB is constant. In other words, it is desired to minimize the variation in the position of the busbar 2 for the multiple caseless capacitors 1 manufactured as much as possible. However, since the specifications of the caseless capacitor 1 vary, it is not necessary for WL=WR, and it is not necessary for LF=LB. Note that the distance L0 may depend on the dimensions of the capacitor element 10, but since the dimensions of the capacitor element 10 are easy to keep constant, the distance L0 is easy to keep constant.

[0019] In particular, when manufacturing the caseless capacitor 1, it is considered that at least one of the distances WL, WR, LF, and LB may change when forming the sealing portion 40. Therefore, in order to suppress such changes, the present inventors have conducted intensive research and have developed the following method for manufacturing the caseless capacitor 1.

[0020] That is, the method for manufacturing the caseless capacitor 1 according to this embodiment includes the following first to third steps.

[0021] 2A and 2B, in the first step, component 100 (capacitor element 10 to which a pair of bus bars 2 are connected and fixed to metal plate 3) is placed in cavity 50 of molding die 5, and metal plate 3 is brought into contact with molding die 5. Here, molding die 5 has a contact surface 6 with which metal plate 3 comes into contact in cavity 50, and a restricting portion 7 that restricts movement of metal plate 3 along contact surface 6.

[0022] In the second step, as shown in Figures 3A and 3B, resin 4 is injected into cavity 50, and capacitor element 10 is embedded in resin 4 while a portion of each of the pair of bus bars 2 protrudes from resin 4, thereby hardening resin 4 to obtain molded product 1.

[0023] In the third step, molded article 1 is removed from mold 5. Molded article 1 removed from mold 5 is caseless capacitor 1 (see FIGS. 4A to 4C).

[0024] 3A and 3B, when resin 4 is injected into cavity 50, movement of metal plate 3 along contact surface 6 is restricted by restricting portion 7 of mold 5. This allows metal plate 3 to remain in the appropriate position (area occupied by contact surface 6) where it is initially placed. Furthermore, since capacitor element 10 is fixed to metal plate 3 in advance, capacitor element 10 also tends to remain in the appropriate position where it was initially placed. Furthermore, since the pair of bus bars 2 are connected to capacitor element 10 in advance, the pair of bus bars 2 also tends to remain in the predetermined positions where it was initially placed.

[0025] Therefore, according to this embodiment, a case is not provided, and the positional accuracy of the busbar 2 with respect to the outer surface of the sealing portion 40 can be improved. Specifically, when the caseless capacitor 1 is repeatedly manufactured, each of the distances WL, WR, LF, and LB can be easily made constant. In other words, for multiple caseless capacitors 1 manufactured, variation in the position of the busbar 2 can be minimized as much as possible.

[0026] 2.Details (1) First embodiment Hereinafter, a method for manufacturing the caseless capacitor 1 according to the first embodiment will be described with reference to the drawings. The method for manufacturing the caseless capacitor 1 according to this embodiment includes a first step (a component mounting step), a second step (a resin injection step), and a third step (a demolding step).

[0027] <1st process> The first step is a component placement step. That is, as shown in Fig. 2A and Fig. 2B, the first step is a step in which the component 100 is placed in the cavity 50 of the forming die 5 and the metal plate 3 is brought into contact with the forming die 5. In the following, the component 100 and the forming die 5 will first be described. Note that in the first step, it is not necessary to hold the pair of bus bars 2 with a jig (not shown).

[0028] <Parts> 1A and 1B, component 100 includes a capacitor element 10, a pair of bus bars 2, and a metal plate 3. The pair of bus bars 2 are connected to capacitor element 10. Capacitor element 10 is fixed to metal plate 3.

[0029] The capacitor element 10 is as described above. In this embodiment, the capacitor element 10 has a three-dimensional shape that is a rectangle with rounded corners when viewed from the front and extends in the front-rear direction. The outer surface of the capacitor element 10 is electrically insulating except for the first end surface electrode 11 and the second end surface electrode 12. The capacitor element 10 has a first flat surface 10a, a second flat surface 10b, a first curved surface 10c, and a second curved surface 10d.

[0030] The first flat surface 10a is a flat surface facing upward.

[0031] The second flat surface 10b is a flat surface facing downward and is on the opposite side of the first flat surface 10a in the up-down direction.

[0032] The first curved surface 10c is a curved surface that is convex to the left when viewed from the front. The first curved surface 10c connects the first flat surface 10a and the second flat surface 10b.

[0033] The second curved surface 10d is a curved surface that is convex to the right when viewed from the front. The second curved surface 10d connects the first flat surface 10a and the second flat surface 10b. In the left-right direction, the second curved surface 10d is the surface on the opposite side to the first curved surface 10c.

[0034] As described above, the pair of bus bars 2 are connected to the capacitor element 10. The first bus bar 21 and the second bus bar 22 protrude upward from the first flat surface 10a of the capacitor element 10. The material of the pair of bus bars 2 is not particularly limited, but may be, for example, copper.

[0035] Capacitor element 10 is fixed to metal plate 3. In this case, "fixed" means fixed to such an extent that capacitor element 10 does not come off metal plate 3 from the start to the end of the next second step. In other words, before the start of the second step, capacitor element 10 may be temporarily fixed (removably fixed) to metal plate 3. This allows the positioning of capacitor element 10 with respect to metal plate 3 to be redone as necessary before the start of the second step.

[0036] The metal plate 3 has a rectangular shape in a plan view. That is, the metal plate 3 has a rectangular shape extending in the left-right direction and the front-rear direction.

[0037] The metal plate 3 has a first surface 31, a second surface 32, and an outer surface 33. The first surface 31 faces downward. The second surface 32 is the surface opposite to the first surface 31. In other words, the second surface 32 faces upward. The outer surface 33 is a side surface that exists between the first surface 31 and the second surface 32. In other words, the outer surface 33 includes all of the side surfaces facing left, right, forward, and rearward. The metal plate 3 is slightly larger than the capacitor element 10 in a plan view. The material of the metal plate 3 is not particularly limited, but may be, for example, aluminum.

[0038] As described above, the insulating layer 42 is interposed between the capacitor element 10 and the metal plate 3. Specifically, the insulating layer 42 is interposed between the second flat surface 10b of the capacitor element 10 and the second surface 32 of the metal plate 3. The insulating layer 42 is not particularly limited, and examples thereof include a prepreg (adhesive sheet) and an adhesive film. The insulating layer 42 can also be formed of an adhesive or a pressure-sensitive adhesive. The capacitor element 10 is fixed to the metal plate 3 by the insulating layer 42. The positioning of the capacitor element 10 with respect to the metal plate 3 can be performed by a known means such as positioning by image processing.

[0039] ≪Mold≫ The mold 5 is box-shaped and opens upward (see Figs. 2A and 2B). The mold 5 has a bottom plate 53, a left wall 54, a right wall 55, a front wall 56, and a rear wall 57. The mold 5 may be made of metal or non-metal.

[0040] The bottom plate 53 has a lower inner surface 50b. The lower inner surface 50b is a surface facing upward and is a surface that forms the lower surface 40b of the sealing portion 40. The lower inner surface 50b has a rectangular shape in a plan view. That is, the lower inner surface 50b has a rectangular shape extending in the left-right direction and the front-rear direction. The lower inner surface 50b is one size larger than the metal plate 3 in a plan view. The lower inner surface 50b includes a contact surface 6 and a non-contact surface 60. The contact surface 6 is a surface that comes into contact with the first surface 31 of the metal plate 3 when the part 100 is placed in the cavity 50 of the molding die 5. The contact surface 6 has a rectangular shape of the same dimensions as the metal plate 3 in a plan view. By matching the outer periphery of the contact surface 6 with the outer periphery of the metal plate 3, the pair of bus bars 2 are positioned in the appropriate position in a plan view. In other words, the area occupied by the contact surface 6 in a plan view is the appropriate position. The non-contact surface 60 is the surface of the lower inner surface 50b excluding the contact surface 6. The non-contact surface 60 has a frame shape surrounding the contact surface 6 in a plan view.

[0041] The left wall 54 is a wall that protrudes upward on the left side of the bottom plate 53. The left wall 54 extends in the front-rear direction. The left wall 54 has a left inner surface 50c. The left inner surface 50c faces to the right and forms the left surface 40c of the sealing portion 40. The left inner surface 50c has a rectangular shape in a side view.

[0042] The right wall 55 faces the left wall 54. That is, the right wall 55 is a wall that protrudes upward on the right side of the bottom plate 53. The right wall 55 extends in the front-to-rear direction. The right wall 55 has a right inner surface 50d. The right inner surface 50d faces left and forms the right surface 40d of the sealing portion 40. The right inner surface 50d has a rectangular shape with the same dimensions as the left inner surface 50c in a side view.

[0043] The front wall 56 is a wall that protrudes upward in front of the bottom plate 53, and is connected to the front of the left wall 54 and the right wall 55. The front wall 56 extends in the left-right direction. The front wall 56 has a front inner surface 50e. The front inner surface 50e faces rearward and forms the front surface 40e of the sealing portion 40. The front inner surface 50e has a rectangular shape when viewed from the front.

[0044] The rear wall 57 faces the front wall 56. That is, the rear wall 57 is a wall that protrudes upward behind the bottom plate 53. The rear wall 57 extends in the left-right direction. The rear wall 57 has a rear inner surface 50f. The rear inner surface 50f faces forward and forms the rear surface 40f of the sealing portion 40. The rear inner surface 50f has a rectangular shape with the same dimensions as the front inner surface 50e when viewed from the front.

[0045] The cavity 50 of the mold 5 is a space having a rectangular parallelepiped shape. That is, the cavity 50 of the mold 5 is a space surrounded by a bottom plate 53, a left wall 54, a right wall 55, a front wall 56, and a rear wall 57. More specifically, the cavity 50 of the mold 5 is a space surrounded by a lower inner surface 50b, a left inner surface 50c, a right inner surface 50d, a front inner surface 50e, and a rear inner surface 50f.

[0046] The forming die 5 has the contact surface 6 and the restricting portion 7 described above. As described above, the contact surface 6 is the surface with which the metal plate 3 comes into contact in the cavity 50. On the other hand, the restricting portion 7 is a portion that restricts the movement of the metal plate 3 along the contact surface 6. In this embodiment, the restricting portion 7 is a portion that restricts the movement of the metal plate 3 within a plane perpendicular to the up-down direction. In other words, the restricting portion 7 is a portion that restricts the movement of the metal plate 3 placed on the contact surface 6 in the left-right and front-back directions.

[0047] In this embodiment, the restricting portion 7 is present on at least a part of the outer periphery of the contact surface 6. The outer periphery of the contact surface 6 is the boundary portion between the contact surface 6 and the non-contact surface 60. Furthermore, the restricting portion 7 includes at least one guide portion 71 (two in this embodiment). The guide portion 71 is present at two diagonally positioned corners of the contact surface 6 that is rectangular in plan view. The guide portion 71 protrudes toward the cavity 50. That is, the guide portion 71 protrudes upward. In this embodiment, the guide portion 71 is L-shaped in plan view. The guide portion 71 is provided so as to follow the above-mentioned corner portion. That is, in the first step, the corner portion of the metal plate 3 is matched with the guide portion 71, and the part 100 is placed in the cavity 50 of the molding die 5.

[0048] <Second process> The second step is a resin injection step. That is, the second step is a step of injecting the resin 4 into the cavity 50 as shown in Figs. 3A and 3B. In this embodiment, a casting method (potting) can be used. The resin 4 is not particularly limited, but may be, for example, a thermosetting resin such as an epoxy resin. The resin 4 may be the same material as the insulating layer 42 or a different material.

[0049] Resin 4 is injected into cavity 50, and when the liquid level of resin 4 reaches a position higher than first flat surface 10a of capacitor element 10 and lower than the upper ends of each of the pair of bus bars 2, the injection of resin 4 is stopped. This allows capacitor element 10 to be buried in resin 4. Also, each of the pair of bus bars 2 can be partially protruded from resin 4. Then, resin 4 is cured in this state to obtain molded product 1.

[0050] <3rd process> The third step is a demolding step. That is, the third step is a step of removing the molded article 1 from the molding die 5. As described above, the molded article 1 removed from the molding die 5 is the caseless capacitor 1 (see Figs. 4A to 4C). Note that, in order to facilitate demolding, the molding die 5 may be provided with an ejector pin (not shown).

[0051] <Action and effect> According to this embodiment, a case is not provided and the positional accuracy of the busbar 2 with respect to the outer surface of the sealing portion 40 can be improved for the following reasons.

[0052] That is, as shown in FIG. 3A and FIG. 3B, when the resin 4 is injected into the cavity 50, the resin 4 may exert a force on the component 100 in the left-right direction or the front-back direction. However, the movement (left-right and front-back movement) of the metal plate 3 along the contact surface 6 is restricted by the restricting portion 7 of the molding die 5. This allows the metal plate 3 to remain in the appropriate position (the area occupied by the contact surface 6) where it is initially placed. In addition, since the capacitor element 10 is fixed to the metal plate 3 in advance, the capacitor element 10 also tends to remain in the appropriate position where it is initially placed. In addition, since the pair of bus bars 2 are connected to the capacitor element 10 in advance, the pair of bus bars 2 also tends to remain in the appropriate position where it is initially placed. Therefore, when the caseless capacitor 1 is repeatedly manufactured, each of the above-mentioned distances WL, WR, LF, and LB is easily made constant. In other words, the variation in the position of the bus bars 2 can be minimized as much as possible for the multiple caseless capacitors 1 manufactured.

[0053] Therefore, according to this embodiment, no case is provided, and the positional accuracy of the busbar 2 with respect to the outer surface of the sealing portion 40 can be improved.

[0054] Also, in this embodiment, the mold clamping and opening steps are not required, thereby improving the productivity of the caseless capacitor 1. Furthermore, in the first and second steps, it is not necessary to hold the pair of bus bars 2 with a jig (not shown), so the steps of attaching and removing the jig are also unnecessary, and the productivity of the caseless capacitor 1 can be further improved.

[0055] In addition, in the first and second steps, since the metal plate 3 and the mold 5 are in contact with each other, the resin 4 is unlikely to penetrate between the first surface 31 of the metal plate 3 and the contact surface 6 of the mold 5. This makes it possible to obtain a caseless capacitor 1 in which the metal plate 3 is exposed to the outside. When the caseless capacitor 1 is charged or discharged, the capacitor element 10 may generate heat, but since the metal plate 3 is exposed to the outside, the heat can be easily released to the outside by the metal plate 3. In addition, since the metal plate 3 is less likely to absorb moisture than the resin 4, the thickness of the sealing portion 40 between the metal plate 3 and the capacitor element 10 can be made thinner than the thickness of the sealing portion 40 at other locations. This makes it possible to reduce the size of the caseless capacitor 1. Of course, since the caseless capacitor 1 does not have a case, it can also be made lighter.

[0056] (2) Second embodiment Next, a method for manufacturing the caseless capacitor 1 according to the second embodiment will be described with reference to the drawings. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals as those in the first embodiment, and detailed description thereof may be omitted.

[0057] In this embodiment, as shown in Figures 5A and 5B, the metal plate 3 has at least one or more (two in this embodiment) through holes 34. The through holes 34 are present at two diagonally positioned corners of the metal plate 3 that is rectangular in plan view. The through holes 34 are holes that penetrate the metal plate 3 in the thickness direction (the direction connecting the first surface 31 and the second surface 32, i.e., the up-down direction). When an insulating layer 42 is present on the second surface 32 of the metal plate 3, the through holes 34 also penetrate the insulating layer 42 in the thickness direction.

[0058] On the other hand, the restricting portion 7 of the molding die 5 includes at least one or more fitting pins 72 (in this embodiment, the same number as the through holes 34). The fitting pins 72 are present at two diagonally positioned corners of the contact surface 6 that is rectangular in plan view, and protrude upward. More specifically, when the metal plate 3 is placed on the contact surface 6 so that the outer periphery of the metal plate 3 matches the outer periphery of the contact surface 6 in plan view, the fitting pins 72 are present at positions where the through holes 34 of the metal plate 3 are present. The fitting pins 72 are pins that fit into the through holes 34.

[0059] In this embodiment, in the first step, the fitting pin 72 is fitted into the through hole 34 of the metal plate 3, and the part 100 is placed in the cavity 50 of the molding die 5. From the viewpoint of suppressing misalignment of the placed part 100 (i.e., misalignment of the metal plate 3 with respect to the contact surface 6), it is preferable that there is less play between the inner diameter of the through hole 34 and the outer diameter of the fitting pin 72.

[0060] <Action and effect> The second embodiment also provides the same effects as the first embodiment.

[0061] In particular, in this embodiment, by fitting the mating pin 72 into the through hole 34 of the metal plate 3 in the first step and placing the part 100 in the cavity 50 of the molding die 5, even if the resin 4 exerts a force on the part 100 in the left-right or front-back direction in the second step, misalignment of the part 100 is suppressed.

[0062] (3) Third embodiment Next, a manufacturing method of the caseless capacitor 1 according to the third embodiment will be described with reference to the drawings. In the third embodiment, the same components as those in the first and second embodiments are denoted by the same reference numerals as in the first and second embodiments, and detailed description thereof may be omitted.

[0063] In this embodiment, as shown in Figs. 6A, 6B, and 6C, the metal plate 3 has at least one (two in this embodiment) non-through hole 35. The non-through hole 35 opens downward. That is, the non-through hole 35 opens in the first surface 31 (the surface facing the contact surface 6) of the metal plate 3. In this embodiment, the non-through hole 35 is a hole having a truncated cone shape. The non-through hole 35 is also present at a position contacting the outer periphery of the capacitor element 10 in a plan view (see Fig. 6A). Particularly in this embodiment, the non-through hole 35 is present at a position contacting the first end surface electrode 11 and the second end surface electrode 12 in a plan view.

[0064] The metal plate 3 also has at least one protruding portion 37 (in this embodiment, the same number as the non-through holes 35). The protruding portion 37 protrudes upward. That is, the protruding portion 37 is a portion that protrudes from the second surface 32 (the surface opposite to the surface facing the contact surface 6) of the metal plate 3 toward the capacitor element 10. The protruding portion 37 is located at the same position as the non-through hole 35 in a plan view. That is, the protruding portion 37 is a portion that is inseparable from the non-through hole 35. Furthermore, in this embodiment, the protruding portion 37 is located at a position that overlaps with the capacitor element 10 in a front view (see FIG. 6B). As a result, in the component 100, the protruding portion 37 is in contact with the capacitor element 10. More specifically, the front protruding portion 37 is in contact with the first end surface electrode 11, and the rear protruding portion 37 is in contact with the second end surface electrode 12. Since the surface of the protruding portion 37 is covered with an insulating layer (see FIG. 6C), the protruding portion 37 is in contact with the first end surface electrode 11 and the second end surface electrode 12 via the insulating layer .

[0065] On the other hand, the restricting portion 7 of the forming die 5 includes at least one (in this embodiment, the same number as the non-through holes 35) engaging protrusion 73. The engaging protrusion 73 is present at a position where the non-through hole 35 of the metal plate 3 is present when the metal plate 3 is placed on the contact surface 6 so that the outer periphery of the metal plate 3 matches the outer periphery of the contact surface 6 in a plan view. The engaging protrusion 73 is a protrusion that protrudes upward and engages with the non-through hole 35. In this embodiment, the engaging protrusion 73 is a protrusion having a truncated cone shape.

[0066] In this embodiment, in the first step, the fitting protrusions 73 are fitted into the non-through holes 35 of the metal plate 3, and the part 100 is placed in the cavity 50 of the molding die 5.

[0067] <Action and effect> The third embodiment also provides the same effects as the first embodiment.

[0068] In particular, in this embodiment, by fitting the mating protrusion 73 into the non-through hole 35 of the metal plate 3 in the first step and placing the part 100 in the cavity 50 of the molding die 5, even if the resin 4 exerts a force on the part 100 in the left-right or front-back direction in the second step, misalignment of the part 100 is suppressed.

[0069] Furthermore, in this embodiment, since two protruding portions 37 are present to sandwich capacitor element 10 in the front-rear direction, displacement of capacitor element 10 relative to metal plate 3 in the front-rear direction can also be suppressed.

[0070] (4) Fourth embodiment Next, a manufacturing method of the caseless capacitor 1 according to the fourth embodiment will be described with reference to the drawings. In the fourth embodiment, the same components as those in the first to third embodiments are denoted by the same reference numerals as those in the first to third embodiments, and detailed description thereof may be omitted.

[0071] In this embodiment, as shown in FIGS. 7A and 7B, the metal plate 3 has a flat portion 30 and at least one or more (two in this embodiment) protruding pieces .

[0072] The flat portion 30 has a rectangular shape in a plan view. That is, the flat portion 30 has a rectangular shape extending in the left-right direction and the front-rear direction. More specifically, the flat portion 30 has a rectangular shape having the same dimensions as the lower inner surface 50b of the bottom plate 53 in a plan view.

[0073] The protruding pieces 36 protrude from at least a part of the outer periphery of the flat portion 30 toward the capacitor element 10. Specifically, the protruding pieces 36 protrude upward from the left end and the right end of the flat portion 30. The protruding pieces 36 extend in the front-rear direction. The protruding pieces 36 are in contact with the capacitor element 10. More specifically, the left protruding piece 36 is in contact with the first curved surface 10c of the capacitor element 10 via the insulating layer 42, and the right protruding piece 36 is in contact with the second curved surface 10d of the capacitor element 10 via the insulating layer 42.

[0074] On the other hand, the regulating portion 7 of the forming die 5 includes a wall portion 74. In this embodiment, the wall portion 74 is at least a part of each of the left wall 54, the right wall 55, the front wall 56, and the rear wall 57 of the forming die 5. The wall portion 74 contacts at least a part (all of the outer surface 33 in this embodiment) of the metal plate 3 (flat portion 30). More specifically, the left inner surface 50c of the left wall 54 contacts the side surface of the metal plate 3 facing the left side. The right inner surface 50d of the right wall 55 contacts the side surface of the metal plate 3 facing the right side. The front inner surface 50e of the front wall 56 contacts the side surface of the metal plate 3 facing forward. The rear inner surface 50f of the rear wall 57 contacts the side surface of the metal plate 3 facing rearward.

[0075] As described above, in this embodiment, the lower inner surface 50b of the bottom plate 53 has the same shape and dimensions as the flat portion 30 of the metal plate 3 in a plan view. In other words, in this embodiment, the lower inner surface 50b includes the contact surface 6 but does not include the non-contact surface 60.

[0076] <Action and effect> The fourth embodiment also provides the same effects as the first embodiment.

[0077] In particular, in this embodiment, when the part 100 is placed in the cavity 50 of the molding die 5, a wall portion 74 is present so as to match the outer periphery of the flat portion 30 of the metal plate 3, thereby further restricting movement along the contact surface 6 of the metal plate 3 (movement in the left-right and front-back directions).

[0078] Furthermore, in this embodiment, since two protruding pieces 36 are present so as to sandwich capacitor element 10 in the left-right direction, movement of capacitor element 10 relative to metal plate 3 in the left-right direction can be suppressed.

[0079] (5) Fifth embodiment Next, a manufacturing method of the caseless capacitor 1 according to the fifth embodiment will be described with reference to the drawings. In the fifth embodiment, the same components as those in the first to fourth embodiments are denoted by the same reference numerals as those in the first to fourth embodiments, and detailed description thereof may be omitted.

[0080] 8A and 8B, in this embodiment, the cavity 50 has a first accommodating portion 51 and a second accommodating portion 52. The first accommodating portion 51 and the second accommodating portion 52 are spaces that are continuous in the vertical direction.

[0081] The first accommodating portion 51 is a plate-shaped space. The first accommodating portion 51 is a space that accommodates at least the metal plate 3 (in this embodiment, the metal plate 3 and the insulating layer 42) of the component 100. In a plan view, the first accommodating portion 51 has the same shape and dimensions as the contact surface 6. There is a step at the boundary between the contact surface 6 and the non-contact surface 60. The contact surface 6 is one step lower than the non-contact surface 60. This makes it easy to fit the metal plate 3 into the first accommodating portion 51.

[0082] The restricting portion 7 is present in the first housing portion 51. The restricting portion 7 includes a wall portion 74. In this embodiment, the wall portion 74 is an inner surface of the first housing portion 51. The wall portion 74 contacts at least a portion (in this embodiment, the entirety) of the outer surface 33 of the metal plate 3.

[0083] On the other hand, second accommodating portion 52 exists above first accommodating portion 51. Second accommodating portion 52 is a space having a rectangular parallelepiped shape. Second accommodating portion 52 is slightly larger than first accommodating portion 51 in a plan view. Second accommodating portion 52 is a space that accommodates at least a portion of component 100 excluding metal plate 3 (capacitor element 10 and a pair of bus bars 2 in this embodiment).

[0084] <Action and effect> The fifth embodiment also provides the same effects as the first embodiment.

[0085] In particular, in this embodiment, when the part 100 is placed in the cavity 50 of the molding die 5, a wall portion 74 is present in the first storage portion 51 so as to match the outer periphery of the metal plate 3, thereby further restricting movement along the contact surface 6 of the metal plate 3 (movement in the left-right and front-back directions).

[0086] (6) Sixth embodiment Next, a manufacturing method of the caseless capacitor 1 according to the sixth embodiment will be described with reference to the drawings. In the sixth embodiment, the same components as those in the first to fifth embodiments are denoted by the same reference numerals as those in the first to fifth embodiments, and detailed description thereof may be omitted.

[0087] In this embodiment, as shown in FIGS. 9A and 9B, the metal plate 3 has a flat portion 30, a first curved portion 30c, and a second curved portion 30d.

[0088] The flat portion 30 has a rectangular shape in a plan view. That is, the flat portion 30 has a rectangular shape extending in the left-right and front-rear directions. The flat portion 30 is a portion that faces the second flat surface 10b of the capacitor element 10. The flat portion 30 has at least one or more through holes 34 (two in this embodiment). The through holes 34 are present in the front and rear of the flat portion 30. The through holes 34 are present in positions that do not overlap with the capacitor element 10 in a plan view (see FIG. 9A).

[0089] The first curved portion 30c is connected to the flat portion 30. Specifically, the first curved portion 30c is connected to the left end portion of the flat portion 30. Furthermore, the first curved portion 30c is curved along the first curved surface 10c of the capacitor element 10.

[0090] The second curved portion 30d is also connected to the flat portion 30. Specifically, the second curved portion 30d is connected to the right end portion of the flat portion 30. Furthermore, the second curved portion 30d is curved along the second curved surface 10d of the capacitor element 10.

[0091] On the other hand, the contact surface 6 of the molding die 5 is the surface with which the first surface 31 of the flat portion 30 of the metal plate 3 comes into contact when the part 100 is placed in the cavity 50 of the molding die 5. The first curved portion 30c and the second curved portion 30d of the metal plate 3 are raised above the lower inner surface 50b of the bottom plate 53, and are therefore embedded in the resin 4 in the second step.

[0092] The restricting portion 7 of the molding die 5 includes at least one (in this embodiment, the same number as the through holes 34) engaging pins 72. When the flat portion 30 of the metal plate 3 is placed on the contact surface 6 so that the outer periphery of the flat portion 30 of the metal plate 3 matches the outer periphery of the contact surface 6 in a plan view, the engaging pins 72 are located at positions where the through holes 34 of the metal plate 3 are located.

[0093] <Action and effect> The sixth embodiment also provides the same effects as the first embodiment.

[0094] In particular, in this embodiment, the flat portion 30, the first curved portion 30c, and the second curved portion 30d of the metal plate 3 are configured to wrap around the lower half of the capacitor element 10 in the left-right direction, thereby preventing the capacitor element 10 from moving in the left-right direction relative to the metal plate 3.

[0095] Furthermore, in this embodiment, by fitting the mating pin 72 into the through hole 34 in the flat portion 30 of the metal plate 3 in the first step and placing the part 100 in the cavity 50 of the molding die 5, even if the resin 4 exerts a force on the part 100 in the left-right or front-back direction in the second step, misalignment of the part 100 is suppressed.

[0096] (7) Seventh embodiment Next, a manufacturing method of the caseless capacitor 1 according to the seventh embodiment will be described with reference to the drawings. In the seventh embodiment, the same components as those in the first to sixth embodiments are denoted by the same reference numerals as those in the first to sixth embodiments, and detailed description thereof may be omitted.

[0097] 10A and 10B, in this embodiment, the metal plate 3 is a magnetic metal plate 38. The magnetic metal plate 38 is a metal plate 3 having magnetism. The material of the magnetic metal plate 38 is not particularly limited, but examples thereof include iron, nickel, and stainless steel.

[0098] On the other hand, the restricting portion 7 of the molding die 5 includes a magnet 61. The magnet 61 is present on the contact surface 6 of the molding die 5, but is not present on the non-contact surface 60. The magnet 61 has the same shape and dimensions as the contact surface 6 in a plan view. The magnet 61 can attract the magnetic metal plate 38.

[0099] <Action and effect> The seventh embodiment also provides the same effects as the first embodiment.

[0100] Particularly in this embodiment, when the part 100 is placed in the cavity 50 of the forming die 5, even if the metal plate 3 is slightly displaced from the correct position (the area occupied by the contact surface 6) in a plan view, the metal plate 3 is a magnetic metal plate 38, and therefore the metal plate 3 is attracted to the correct position by the attractive force of the magnet 61. In other words, the part 100 is attracted to the correct position.

[0101] Furthermore, in this embodiment, even if the resin 4 exerts a force on the component 100 in the left-right or front-back direction in the second step, the attractive force of the magnet 61 to the magnetic metal plate 38 prevents the component 100 from shifting out of position.

[0102] 3. Variations Although each embodiment has been described above, each embodiment can be modified as appropriate without departing from the technical concept thereof.

[0103] In each embodiment, the metal plate 3 (flat portion 30) has a rectangular shape in a plan view, but there is no particular limitation on the shape of the metal plate 3. On the other hand, the contact surface 6 of the molding die 5 has the same shape and dimensions as the metal plate 3 in a plan view.

[0104] In each embodiment, the sealing portion 40 of the caseless capacitor 1 has a rectangular parallelepiped shape, but the shape of the sealing portion 40 is not particularly limited. [Explanation of symbols]

[0105] 1 Caseless capacitor (molded product) 10 Capacitor element 10a 1st flat surface 10b 2nd flat surface 10c First curved surface 10d Second curved surface 2 Busbars 3 metal plate 30 Flat area 30c First curved section 30d Second curved section 33 External surface 34 Through hole 35 Non-through hole 36 Projecting piece 37 Protrusion 38 Magnetic metal plate 4. Resin 42 Insulating layer 5 Molding mold 50 Cavity 6 Contact surface 61 Magnet 7. Regulatory Department 71 Guide part 72 Mating Pin 73 Fitting protrusion 74 Wall

Claims

1. a first step of placing a capacitor element having a pair of bus bars connected thereto and fixed to a metal plate in a cavity of a molding die and bringing the metal plate into contact with the molding die; a second step of injecting a resin into the cavity to embed the capacitor element in the resin and hardening the resin in a state in which each of the pair of bus bars is partially protruding from the resin, thereby obtaining a molded product; A third step of removing the molded product from the mold, The molding die has a contact surface with which the metal plate comes into contact in the cavity, and a regulating portion that regulates movement of the metal plate along the contact surface. Manufacturing method for caseless capacitors.

2. an insulating layer is interposed between the capacitor element and the metal plate, and the capacitor element is fixed to the metal plate by the insulating layer; A method for manufacturing the caseless capacitor according to claim 1.

3. The restricting portion includes a guide portion that is present on at least a part of an outer periphery of the contact surface and protrudes toward the cavity. A method for manufacturing the caseless capacitor according to claim 1 or 2.

4. the metal plate has a through hole penetrating in a thickness direction of the metal plate, The restricting portion includes a fitting pin that fits into the through hole. A method for manufacturing the caseless capacitor according to any one of claims 1 to 3.

5. the metal plate has a blind hole that opens to a surface facing the contact surface, The restricting portion includes a fitting protrusion that fits into the non-through hole. A method for manufacturing the caseless capacitor according to any one of claims 1 to 4.

6. The restricting portion includes a wall portion that contacts at least a portion of the outer surface of the metal plate. A method for manufacturing the caseless capacitor according to any one of claims 1 to 5.

7. the metal plate has a flat portion and a protruding piece that protrudes from at least a part of an outer periphery of the flat portion toward the capacitor element and contacts the capacitor element; A method for manufacturing the caseless capacitor according to any one of claims 1 to 6.

8. the capacitor element has a first flat surface, a second flat surface opposite to the first flat surface, a first curved surface connecting the first flat surface and the second flat surface, and a second curved surface connecting the first flat surface and the second flat surface and opposite to the first curved surface; The metal plate has a flat portion facing the second flat surface, a first curved portion connected to the flat portion and curved along the first curved surface, and a second curved portion connected to the flat portion and curved along the second curved surface. A method for manufacturing the caseless capacitor according to any one of claims 1 to 7.

9. the metal plate has a protruding portion that protrudes toward the capacitor element from a surface opposite to the surface facing the contact surface and that contacts the capacitor element; A method for manufacturing the caseless capacitor according to any one of claims 1 to 8.

10. the metal plate is a magnetic metal plate, a magnet that attracts the magnetic metal plate is present on the contact surface of the mold; A method for manufacturing the caseless capacitor according to any one of claims 1 to 9.

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